Armature-core



1. B. BUSHNELL.

ARMATURE CORE.

APPLICATION FILED NOV. 23. ISIS.

Patented Jan. 11, 1921.

I Y M Big. 6'

IN VENTOR. ]0]2nB.Bas/?J2 6'Zl i i ATTORNEY UNITED STATES ATENT OFFICE.

JOHN B. BUSHNELL, OF BERKELEY, CALIFORNIA, ASSIGNOR TO BUSHNELL MAGNETOCOMPANY, OF SAN FRBN'CISC'O, CALIFORNIA, A CORPORATION.

ARMATURI]-GORE.

T 0 all whom it may concern Be it known that I, JOHN B. BUSHNELL, acitizen of the United States of America, residing at Iierkeley, in thecounty of Alameda, State of California, have invented certain new anduseful Improvements in Armature-Cores; and I do declare the following tobe a clear, full, and exact description of the same, reference being hadto the accompanying drawings, and to the characters of reference markedthereon, which form a part of this application.

This invention relates to improvements in magneto construction andparticularly to the armature core per 86.

The object of the invention is to produce an armature core which willenhance the output of current from the windings by reason ofconcentrating the magnetic flux to an iron web, the said web beingintegral with the solid iron rim pieces. I use silicon steel laminationsin my armature to break up eddy currents, these laminations being put inslots cut across and through the rims on each side of the web, thelaminations being insulated and then pressed into place. This is allthat is required to hold them in position, eliminating the use of screwsor rivets which are commonly used in other cores. By eliminating theseholding screws or rivets which go transversely through the length of thecore I eliminate eddy currents which these screws or rivets cause. It iswell known that eddy currents in a permanent magnet machine tend tointerfere with or retard the easy passage of the magnetic flux. Eddycurrents cause losses through dissipation of heat. It will be seen thatby reducing eddy currents and other losses caused therefrom to aminimum, my armature core will give a higher efficiency. Another objectof the invention therefore is to produce an armature core which willhave a quicker reversal of polarity than other commonly used armaturesbecause of eliminating these eddy currents and losses caused throughheat and the dissipation of energy.

A further object is to produce a simple and inexpensive device and yetone which will be exceedingly eifective for the purposes for which it isdesigned.

These objects I accomplish by means of such structure and relativearrangement of Specification of Letters Patent.

Patented Jan. 11, 1921.

Serial No. 263,835.

the parts as will fully appear by a perusal of the followingspecification and claims.

On the drawings, similar characters of reference indicate correspondingparts in the several v'ews.

Figure l is a side elevation of the complete core.

Fig. 2 is an end view of the same.

Fig. 3 is a view similar to Fig. l but showing the insulated steellaminations removed.

Fig. 4: is a sectional view taken on a line a-l of Fig. 3.

F ig. 5 is a plan view of the core showing how the center web makes acontinuous iron connection between the rim pieces and holds the steellaminations separated on each side thereof.

F 6 is a side elevation of one of the steel laminations.

Referring now more particularly to the characters of reference on thedrawings, the numeral 1 designates the rim pieces each being in itself asolid segmental iron piece of equal arcuate width with the other and thetwo being connected by an integral iron cross web 2, diametricallypositioned relative to the segments and extending lengthwise thereof.

Each piece 1 on each=side of the web 2 is provided with a cut in recess3. con steel laminations l, insulated in the usual manner as at 5, arereceived into these recesses 3 under pressure. Thus they arefrictionally held in place without the necessity of using transverselyarranged securing members.

By thus eliminating transverse securing members as commonly used inother cases, I remove an instrumentality tending to produce eddycurrents and a consequent dissipation of energy. The current output of amagneto using my improved core will he therefore greatly enhanced.

Thus, from the foregoing description it will readily be seen that I haveproduced such a device as substantially fulfils the objects of theinvention as set forth herein.

While this specification sets forth in detail the present and preferredconstruction of the device, still in practice, such deviations from suchdetail may be resorted to as do not form a departure from the spirit Thesili of the invention, as defined by the appended claims.

Having thus described my invention, what I claim as new and useful anddesire to secure by Letters Patent is 1. An armature core consisting ofrim pieces spaced apart, an iron web connecting the same and insulatedlaminations of metal arranged on each side of the web.

2. An armature core comprising two solid rim pieces spaced apart, anintegral iron web connecting the two, the rims each being provided witha recess on each side of the web and insulated metal laminationsreceived under pressure into the recesses on each side of the web, andextending between the rims.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN B. BUSHNELL.

\Vitnesses:

VnRADrNn VVARNER, BERNARD PRIVAT.

